JP2002069017A - Method for producing fluorinated alcohol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a fluorinated alcohol expressed by the general formula (1): H(CFR1CF2)nCH2OH [(n)=1 or 2; when (n)=1, R1 is F or CF3, and when (n)=2, R1 is F], substantially free from an impurity and capable of reusing methanol. SOLUTION: This method for producing the fluorinated alcohol is provided by (i) reacting methanol with tetrafluoroethylene, etc., in the presence of a radical-generating agent and an acid-accepting agent, (ii) removing the reaction product of the acid-accepting agent and unreacted acid-accepting agent from the obtained crude reaction material, (iii) introducing the crude reaction material treated in the above (ii) to a distillation column, distilling off methanol together with the remaining radical initiating agent from the top of the column and taking out a bottom component containing the fluorinated alcohol expressed by the formula (1) from the bottom of the column, (iv) returning the fraction obtained from the top of the column to the reaction vessel for reusing and (v) recovering the fluorinated alcohol expressed by the formula (1) by fractionating the above bottom component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a compound represented by the general formula (1) H (CFR ¹ CF ₂ ) _n CH ₂ OH (1) [n = 1 or 2. When n = 1, R ¹ represents F or CF ₃ . When n = 2, R ¹ indicates F. ] The method for producing a fluoroalcohol represented by the formula:

[0002]

_2. Description of the Related Art H (CF ₂ CF ₂ ) _n CH ₂ OH (n = 1,
The production method of 2) is disclosed in JP-A-54-154707 and U.S. Pat. No. 2,559,628 by reacting methanol and tetrafluoroethylene in the presence of a radical generator, t-butyloctyl peroxide. It is stated that a telomer mixture of (CF ₂ CF ₂ ) _n CH ₂ OH (n up to 12) is obtained.

In this method, since an excessive amount of methanol is used, it is desirable to recover and reuse the methanol contained in the crude reaction product. For example, Japanese Patent No. 30280
No. 4 discloses a method for producing fluoroalcohol including a step of recycling methanol. On the other hand, the telomer mixture is distilled in a state where the radical generator remains undecomposed in the crude reaction product or in a state where an unreacted acid acceptor and the like remain in the crude reaction product using an acid acceptor. In order to obtain the desired fluoroalcohol by evaporation, the evaporation residue, U
An information recording medium in which impurities such as V-absorbing components are included in the recovered fluorine alcohol, and a recording layer on which information can be written and / or read by a laser is provided on a substrate such as a CD-R or DVD-R. When used as a solvent during production, there is a disadvantage that it is not suitable for producing a high-quality information recording medium.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a compound of the general formula (1) H (CFR ¹ CF ₂ ) _n CH ₂ OH (1) [n] which is substantially free from impurities and which can reuse methanol. = 1 or 2. When n = 1, R ¹ represents F or CF ₃ . When n = 2, R ¹ indicates F. And a method for producing a fluoroalcohol represented by the formula:

[0005]

The present invention relates to the inventions described in the following items.

Item 1 In the presence of a radical generator and an acid acceptor, starting from methanol and tetrafluoroethylene or hexafluoropropylene, the following formula (1) H (CFR ¹ CF ₂ ) _n CH ₂ OH (1) [N = 1 or 2. When n = 1, R ¹ represents F or CF ₃ . When n = 2, R ¹ indicates F. A method for producing a fluoroalcohol represented by the following method, comprising the following steps (i) to (v): (i) reacting methanol with tetrafluoroethylene or hexafluoropropylene, ii) removing the reaction product of the acid acceptor and the unreacted acid acceptor from the obtained reaction crude product, (iii) introducing the reaction crude product treated in the above (ii) step to a distillation column, and methanol Is distilled off from the top of the reaction product together with the radical generator remaining in the reaction crude product, and a bottom component containing a fluorine alcohol represented by the formula (1) is taken out from the bottom of the reaction. (V) a step of purifying the bottom component to recover the fluoroalcohol represented by the formula (1).

Item 2 In a method for producing HCF ₂ CF ₂ CH ₂ OH using methanol and tetrafluoroethylene as starting materials in the presence of a radical generator and an acid acceptor, the following steps (i) to (vi) are performed: A method characterized by including: (i) a step of reacting methanol with tetrafluoroethylene; and (ii) a step of removing a reaction product of an acid acceptor and a residue of the acid acceptor from the obtained reaction crude product. (Iii) The above (i
i) The reaction crude product treated in the step is led to the first distillation column, and methanol is distilled off from the top of the column together with the radical generator remaining in the reaction crude product. From the bottom, the general formula (2) H (CF ₂ CF ₂ ) _l CH ₂ OH (2) a step of taking out a bottom component containing a fluoroalcohol represented by [l = 1 to 5], (iv) returning the fraction obtained from the top to the reactor And (v) guiding the bottom component obtained in the step (iii) to a second distillation column, distilling HCF ₂ CF ₂ CH ₂ OH from the top of the column, Removing the bottom component containing 2 or more fluorine alcohols in 2), and (vi)
(v) HCF ₂ CF ₂ C distilled off from the top in the process
Recovering HCF ₂ CF ₂ CH ₂ OH by contacting H ₂ OH with a base or distilling in the presence of a base.

[0008] In the method of claim 3, wherein 2, a method of recovering the HCF ₂ CF ₂ CH ₂ OH in (vi) step, HCF ₂
After distilling a component containing CF ₂ CH ₂ OH to remove a low-boiling component, the HCF ₂ CF ₂ CH ₂ obtained as a bottom component was removed.
The component containing OH is distilled again to obtain HCF ₂ CF ₂ CH ₂ OH.
And a method for producing a fluorinated alcohol.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the step of reacting methanol with tetrafluoroethylene or hexafluoropropylene in the presence of a radical generator, an excess amount of methanol is used with respect to tetrafluoroethylene or hexafluoropropylene. The reaction temperature is about 40 to 140 ° C., the reaction time is about 3 to 12 hours, and the reaction pressure is 0.2 to 1.2.
It is on the order of MPa. The reaction can be performed in a high-pressure reactor such as an autoclave. Nitrogen in the reaction system,
It is preferable to replace with an inert gas such as argon.

As the radical generator, those which can be distilled off together with methanol when distilled are used. These radical generators need only be able to be distilled off together with methanol, and may be those that decompose in the course of distillation.

Specifically, di-t-butyl peroxide [boiling point 109-110 ° C.] (trade name “Perbutyl D”)
(Available as NOF Corporation), t-butylperoxy-2-ethylhexanoate (available as trade name "Perbutyl O" (available from NOF Corporation)), t-butylperoxy Peroxides such as isopropyl carbonate (available as trade name "Perbutyl I" (manufactured by NOF Corporation)) and the like are preferred. Among them, di-t
Preference is given to using butyl peroxide.

The amount of the radical generator used is usually about 0.005 to 0.1 mol per mol of tetrafluoroethylene or hexafluoropropylene.

The above reaction is carried out in the presence of an acid acceptor. Examples of the acid acceptor include carbonates and bicarbonates of alkali metals or alkaline earth metals such as calcium carbonate, magnesium carbonate, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate, calcium oxide, calcium hydroxide, and soda. Lime, barium carbonate and the like can be mentioned. The acid acceptor is preferably capable of trapping an acid such as HF generated during the reaction without making the reaction system strongly alkaline.

The amount of the acid acceptor used is not particularly limited.
The amount may be about 0.001 to 0.1 mol per 1 mol of tetrafluoroethylene or hexafluoropropylene.

As shown in FIG. 1, the reaction crude product obtained by the above method is led from the reactor to a distillation column, and the distillation column is heated to distill methanol from the top. When the reaction is carried out under the above-described conditions, a part of the radical generator usually remains undecomposed in the crude reaction product, but the radical generator used in the present invention is distilled together with methanol when distilled. Since it is a radical generator to be obtained, the usual distillation conditions for methanol, for example, the pressure in the distillation column is about -0.05 to 0.1 MPa (indicating a gauge pressure.
same as below. The still is heated and distilled while controlling to
If methanol is distilled at about 40 to 90 ° C., the radical generator remaining in the reaction crude product is distilled together with methanol. Thus, the radical generator remaining undecomposed can be removed from the crude reaction product.

In the present invention, it is sufficient that the undecomposed radical generator remaining in the reaction crude can be removed from the reaction crude, the radical generator itself may be distilled together with methanol, and the radical generator may be removed in the course of distillation. The generator may be decomposed, and the decomposed product may be distilled together with methanol. Therefore, the fraction containing methanol may contain an undecomposed radical generator, may contain a decomposition product of the radical generator, or may contain both of them. For example, among the radical generators exemplified above, when t-butyl peroxide is used,
Since it hardly decomposes in the course of distillation, t-butyl peroxide is distilled off together with methanol.

The crude reaction product of methanol and tetrafluoroethylene or hexafluoropropylene may contain HF and water, which are concentrated in the middle stage of the distillation column. The layer where HF and water are concentrated,
As shown in FIG. 2, it can be withdrawn from the distillation column as a side cut fraction. The temperature of the side cut fraction is 8
It is about 0 to 120 ° C./0.1 MPa.

In the present invention, before the crude reaction product is introduced into the distillation column, the reaction product of an acid acceptor such as CaF ₂ and NaF and the unreacted acid acceptor are removed from the crude reaction product. This operation is not particularly limited, and any method may be used as long as it can remove the reaction product of the acid acceptor and the unreacted acid acceptor from the reaction crude product. For example, as shown in FIG. By using it, it can be efficiently removed.

The fraction obtained from the top of the column is returned to the reactor and reused as shown in FIGS. When a radical generator is contained in the fraction without being decomposed, the radical generator can also be reused. Even when the fraction contains a decomposition product of the radical generator, the fraction can be returned to the reactor as it is and reused.

After the distillation of methanol, it is preferable that all of the remaining radical generator is removed from the bottom component containing the mixture of the fluorine alcohol remaining in the still. The amount is about 1,000 mass ppm or less, preferably 50 mass ppm
It should be less than or equal to about.

The bottom component is taken out from the bottom of the column and
As shown in ( ₂ ) and ( ₂ ), H (CF ₂ CF ₂ ) _n CH ₂ OH (n is 3 or more), H (CF (CF ₃ ) CF ₂ ) _n By removing impurities such as CH ₂ OH (n is 2 or more), the general formula (1) H (CFR ¹ CF ₂ ) _n CH ₂ OH (1) [n = 1 or 2. When n = 1, R ¹ represents F or CF ₃ . When n = 2, R ¹ indicates F. ] Is recovered. In the case of using tetrafluoroethylene as the starting material, since the bottom component include HCF ₂ CF ₂ CH ₂ OH and _{H (CF 2 CF 2) 2} CH 2 OH, in the purification step, from the bottom components, HCF ₂ CF ₂ CH ₂ OH
And H (CF ₂ CF ₂ ) ₂ CH ₂ OH may be sequentially separated.

In the method of the present invention, after the above-mentioned purification step, H (CFR ¹ CF ₂ ) _n CH ₂ OH of the formula (1)
(1) [n and R ¹ are as defined above. ]
May be recovered after contacting with a base or in the presence of a base. By performing such an operation, a fluorine alcohol of the formula (1) having a lower impurity content can be obtained. At this time, a base may be directly added to the middle part or the still of the distillation column, or a treatment tank (base treatment tank) may be provided before the distillation column. When a base treatment tank is provided, the operating conditions in the treatment tank are not particularly limited.
After adding the base, the reaction may be performed at about 20 to 150 ° C. for about 0.5 to 3 hours. Alternatively, methanol and tetrafluoroethylene are used as raw materials to prepare HCF ₂ CF ₂ CH
_When producing ₂ OH, a bottom component containing a fluoroalcohol represented by the general formula (2) H (CF ₂ CF ₂ ) ₁ CH ₂ OH (2) [l = 1 to 5] is led to a distillation column. To perform HCF ₂ CF ₂ CH
_After distilling off the ₂ OH and contacting the fraction with a base or by further distillation in the presence of a base, HCF ₂ C
F ₂ CH ₂ OH can be recovered. From the bottom of the column, a bottom component containing a fluorine alcohol having 1 or more in formula (2) is taken out.

As the base, a base having a pKb of 2 or less is preferable. Such bases include sodium carbonate,
Alkali metal carbonates such as potassium carbonate; alkali metal bicarbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate; alkali metals such as sodium methylate, sodium ethylate, sodium propylate, potassium t-butoxide, lithium ethylate Alcoholates; hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide and lithium hydroxide; hydroxides of alkaline earth metals such as calcium hydroxide, magnesium hydroxide and barium hydroxide; aluminum hydroxide, soda lime And the like. These bases may be used alone or in combination of two or more.

The amount of the base to be used can be appropriately set, and is usually about 0.05 to 1.0 mol per 1 kg of the weight of the fluoroalcohol of the general formula (1) brought into contact with the base.
Preferably it is about 0.1 to 0.5 mol.

When treating with a base, alcohol, water, etc. are produced as reaction products depending on the type of base used,
Low-boiling components such as alcohol used as a solvent for the reaction product and the base are mixed into the fluorine alcohol of the formula (1).
Therefore, in order to obtain a high-purity fluoroalcohol of the formula (1), first, as a first-stage distillation operation, alcohol, water, etc., which are low-boiling components, are separated and removed from the fluoroalcohol of the formula (1). Then, as a second step, the component containing the fluorine alcohol of the formula (1) obtained as the bottom component by the distillation operation of the first step is distilled to recover the fluorine alcohol of the formula (1). preferable. One embodiment of such a distillation method is shown in FIG. According to such a distillation method, it is possible to obtain a fluoroalcohol of the formula (1) substantially free from impurities and containing no alcohol or water.

In place of such a two-stage distillation operation, low-boiling components such as alcohol and water are sequentially removed by distillation, and then the fluorine alcohol of the formula (1) is recovered from the top or the middle of the distillation column. It is also possible.

In the method of the present invention, any of the distillation methods may be employed, but the two-stage distillation method can easily recover the high-purity fluorine alcohol of the formula (1).

The reaction between methanol and tetrafluoroethylene or hexafluoropropylene is usually carried out in a batch process, but the process after the reaction may be a batch process or a continuous process.

According to the production method of the present invention, the evaporation residue is 5%.
A fluoroalcohol of the formula (1) having a content of 0 ppm or less, preferably 25 ppm or less, more preferably 10 ppm or less is obtained.

The evaporation residue can be determined as follows. That is, fluorinated alcohol at 40 ° C., 5 mmH
The weight of the residue after evaporation in g is measured and expressed as mass ppm relative to fluoroalcohol.

The UV absorbance at 205 nm of methanol of the fluoroalcohol of the general formula (1) obtained in the present invention is 0.1 abs or less, preferably -0.1 abs or less.
More preferably, it is -0.2 abs or less. The UV absorbance in methanol is 1 m of fluoroalcohol of the general formula (1).
The measurement is made by adding 3 ml of methanol to 1 and using methanol as a reference.

The fact that the fluoroalcohol obtained by the production method of the present invention is "substantially free from impurities" means that (i) the evaporation residue of the fluoroalcohol is 50 ppm or less, preferably 25 ppm or less, more preferably 10 ppm or less. And / or (ii) UV absorbance (205 nm) in methanol of 0.1 abs or less, preferably -0.1 a
bs or less, more preferably -0.2 abs or less.

An information recording medium in which a recording layer on which information can be written and / or read by a laser is provided on a substrate is a solvent containing a fluorine alcohol of the general formula (1) of the present invention, preferably the fluorine alcohol. Dissolve the dye in a fluorinated solvent containing, apply the resulting solution on the substrate,
It can be manufactured by forming a recording layer containing a dye according to a conventional method such as drying. Examples of the dye include a cyanine dye, a phthalocyanine dye, a pyrylium dye, a thiopyrylium dye, a squarylium dye, an azulenium dye, an indophenol dye, an indoaniline dye, a triphenylmethane dye, a quinone dye, and an aminium dye. Dyes, diimmonium dyes, metal complex dyes, and the like. Examples of the substrate include plastics such as polycarbonate, polymethyl methacrylate, epoxy resin, amorphous polyolefin, polyester, and polyvinyl chloride, glass, and ceramics. In addition, an undercoat layer may be provided between the recording layer and the substrate for the purpose of improving flatness, improving adhesive strength, preventing deterioration of the recording layer, or a protective layer may be provided on the recording layer. .

[0034]

According to the present invention, an information recording medium (such as an optical disk such as a CD-R or DVD-R) having a recording layer on which information can be written and / or read by a laser on a substrate, a film, and the like. Suitable for the production of photoreceptors, etc.
HCF ₂ CF ₂ CH ₂ OH, H substantially free of impurities
(CF ₂ CF ₂ ) ₂ CH ₂ OH and HCF (CF ₃ ) CF ₂ C
H ₂ OH can be easily produced, and the fraction containing the recovered methanol and the radical generator contained in the fraction can be effectively used.

[0035]

The present invention will be described below in more detail with reference to examples.

Example 1-1 Methanol (1500 g) and Perbutyl D were placed in a high-pressure reactor.
(Di-t-butyl peroxide, 31.25 g) and calcium carbonate (6.5 g). After the reactor was replaced with nitrogen, the temperature was raised to 125 ° C., and the reaction was carried out for 2.6 hours while charging tetrafluoroethylene at a pressure of 0.85 MPa. After cooling the reaction crude, the weight was measured to be 2270 g, and analysis by gas chromatography revealed that 15.5 g of perbutyl D remained undecomposed.

The obtained crude reaction product was treated by the following method according to the flowchart shown in FIG.

First, the reaction crude product was introduced from the reaction vessel 1 to the centrifugal separator 3, and after removing the reaction product of the acid acceptor and the unreacted acid acceptor by centrifugation, the reaction crude product was introduced to the first distillation column 4. .

Next, the still was heated while controlling the pressure of the distillation column at 0.1 MPa. From the top of the first distillation column 4, methanol was distilled at a distillation temperature of 80 to 90 ° C. The obtained fraction was 1261.5 g. When this fraction was analyzed, 13.0 g of perbutyl D was contained, and perbutyl D remaining in the crude reaction product together with methanol was contained.
However, it was found that distilling was performed with almost no decomposition.
The bottom component did not contain any perbutyl D.

Next, the bottom component was taken out from the bottom of the first distillation column 4 and led to a purification step by distillation. The bottom component is led to the second distillation column 5 and HCF ₂ CF ₂ C
H ₂ OH (648.3 g) was distilled off, and H (CF ₂ CF
₂ ) _l CH ₂ OH (l is an integer of 2 or more) was taken out from the bottom of the column. A part of the obtained HCF ₂ CF ₂ CH ₂ OH (150
g) was taken out, led to a base treatment tank 6, and sodium methylate (6 g, about 0.03 mol; as a 28% methanol solution) was added to the fraction. Next, the HCF ₂ CF ₂ CH ₂ OH treated with the base is led to the alkali distillation column 7,
Distillation to distill methanol and water from the top, HCF
_The bottom component containing ₂ CF ₂ CH ₂ OH is converted to an alkali distillation column 8.
Sent to Finally, HCF ₂ CF ₂ CH ₂ OH was recovered as a fraction at the middle stage by distillation in the alkali distillation column 8. The evaporation residue of the obtained HCF ₂ CF ₂ CH ₂ OH was 10 ppm, and the UV absorbance (205 nm) was −
It was 0.2 abs or less.

Example 1-2 Perbutyl D (13.0 g) recovered in Example 1-1
1261.5 g of methanol containing
Reused. That is, 254 g of new methanol was added to the recovered methanol, and perbutyl D (15.75 g) and calcium carbonate (6.5 g) were charged.
The reaction was carried out in the same manner as described above. The reaction time was 2.7 hours. After the completion of the reaction, the reaction crude was cooled and weighed 2265 g. Analysis by gas chromatography revealed that 15.1 g of perbutyl D remained without decomposition.

The obtained crude reaction product was treated in accordance with the flow chart shown in FIG. 3 in the same manner as in Example 1-1.

That is, first, the reaction crude product was guided from the reaction vessel 1 to the centrifugal separator 3 to remove the reaction product of the acid acceptor and the unreacted acid acceptor, and then to the first distillation column 4.

Next, the still was heated while controlling the pressure of the distillation column at 0.1 MPa. From the top of the first distillation column 4, methanol was distilled at a distillation temperature of 80 to 90 ° C. The obtained fraction was 1262.3 g. When this fraction was analyzed, 12.6 g of perbutyl D was contained, and perbutyl D remaining in the reaction crude product together with methanol was contained.
However, it was distilled out with almost no decomposition. The bottom component did not contain any perbutyl D.

Next, the bottom component was taken out from the bottom of the first distillation column 4 and led to a purification step by distillation. The bottom component is led to the second distillation column 5 and HCF ₂ CF ₂ C
H ₂ OH (644.1 g) was distilled off and H (CF ₂ CF
₂ ) A bottom component containing ₁ CH ₂ OH (1 is an integer of 2 or more) was taken out from the bottom of the column. HCF ₂ CF ₂ CH ₂ O obtained
A portion (150 g) of H was taken out, led to the base treatment tank 6, and 28% sodium methylate (6 g, about 0.03 mol) was added to the fraction. Then, the HCF ₂ CF ₂ CH ₂ OH which has been treated with a base leads to alkali distillation column 7 and distilled to distill the methanol and water from the top, HCF ₂
The bottom component containing CF ₂ CH ₂ OH was sent to the alkaline distillation column 8. Finally, HCF ₂ CF ₂ CH ₂ OH was recovered as a fraction at the middle stage by distillation in the alkali distillation column 8. The evaporation residue of the obtained HCF ₂ CF ₂ CH ₂ OH was 10 ppm, and the UV absorbance (205 nm) was −0.1.
It was less than 2 abs.

[Brief description of the drawings]

FIG. 1 is a process chart showing one embodiment of the present invention.

FIG. 2 is a process chart showing one embodiment of the present invention, including a step of extracting a side cut fraction.

FIG. 3 is a process diagram showing one embodiment of the present invention, including a two-stage alkali distillation process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reactor 2 Distillation tower 3 Centrifuge 4 First distillation tower 5 Second distillation tower 6 Base treatment tank 7, 8 Alkali distillation tower

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toru Yoshizawa 1-1, Nishiichitsuya, Settsu-shi, Osaka Daikin Industries, Ltd. Yodogawa Works (72) Inventor Kazuyoshi Ichihara 1-1-1, Nishiichitsuya, Settsu-shi, Osaka Daikin Industries 4H006 AA02 AC21 AD11 AD17 BA92 BA93 BD40 BD52 BD60 BE10 BE11 BE12 BE13 FE11 FE71 FE74

Claims (3)

[Claims] 1. In the presence of a radical generator and an acid acceptor,
Starting from methanol and tetrafluoroethylene or hexafluoropropylene, the following formula (1) H (CFR ¹ CF ₂ ) _n CH ₂ OH (1) [n = 1 or 2. When n = 1, R ¹ represents F or CF ₃ . When n = 2, R ¹ indicates F. A method for producing a fluoroalcohol represented by the following method, comprising the following steps (i) to (v): (i) reacting methanol with tetrafluoroethylene or hexafluoropropylene, ii) removing the reaction product of the acid acceptor and the unreacted acid acceptor from the obtained reaction crude product, (iii) introducing the reaction crude product treated in the above (ii) step to a distillation column, and methanol Is distilled off from the top of the reaction product together with the radical generator remaining in the reaction crude product, and a bottom component containing a fluorine alcohol represented by the formula (1) is taken out from the bottom of the reaction. (V) a step of purifying the bottom component to recover the fluoroalcohol represented by the formula (1). _2. A method for producing HCF ₂ CF ₂ CH ₂ OH using methanol and tetrafluoroethylene as starting materials in the presence of a radical generator and an acid acceptor,
A method characterized by comprising the following steps (i) to (vi): (i) a step of reacting methanol with tetrafluoroethylene, (ii) a reaction product of an acid acceptor from the obtained reaction crude product, and (Iii) removing the residue of the acid acceptor;
i) The reaction crude product treated in the step is led to the first distillation column, and methanol is distilled off from the top of the column together with the radical generator remaining in the reaction crude product. From the bottom, the general formula (2) H (CF ₂ CF ₂ ) _l CH ₂ OH (2) a step of taking out a bottom component containing a fluoroalcohol represented by [l = 1 to 5], (iv) returning the fraction obtained from the top to the reactor And (v) guiding the bottom component obtained in the step (iii) to a second distillation column, distilling HCF ₂ CF ₂ CH ₂ OH from the top of the column, Removing the bottom component containing 2 or more fluorine alcohols in 2), and (vi)
(v) HCF ₂ CF ₂ C distilled off from the top in the process
Recovering HCF ₂ CF ₂ CH ₂ OH by contacting H ₂ OH with a base or distilling in the presence of a base. 3. A according to claim 2 method, a method of recovering HCF ₂ CF ₂ CH ₂ OH in (vi) step, HCF ₂
After distilling a component containing CF ₂ CH ₂ OH to remove a low-boiling component, the HCF ₂ CF ₂ CH ₂ obtained as a bottom component was removed.
The component containing OH is distilled again to obtain HCF ₂ CF ₂ CH ₂ OH.
And a method for producing a fluorinated alcohol.